For example, even if a drill made of hard cemented carbide is used in a case in which drilling is performed on a work material made of CFRP (carbon fiber-reinforced plastic) or a work material that is made of a composite material in which a plate made of titanium, aluminum, or an alloy of titanium and aluminum is laminated on CFRP, the wear of the drill is generated and the drill reaches the end of their tool life early. Accordingly, for example, U.S. Patent Application Publication No. 2011/0176879 proposes that the pre-compacted body of PCD be held in a carrier body formed of cemented carbide and is sintered at ultra-high pressure and ultra-high temperature to form a superhard body including a PCD layer, and the superhard body is mounted on the tip of a tool body and flutes are formed to manufacture a rotary machine tool, such as a drill or an end mill, including cutting edges on the PCD layer.